Load sensing includes measuring the force or pressure applied to a surface. It is widely used to measure the weight of goods, to monitor the strain on structures, and to gauge filling levels of containers.
Load sensing has also been used, to a limited degree, to capture contextual information, such as identity and location of people and objects, and the detection of activity. For example, segmented surfaces composed of load-sensitive tiles have been used to identify and track people. Similarly, a grid of piezoelectric wires under a carpet has been used to track the movement of people in artistic performances. It is also possible to perform object identification by temporarily linking a virtual object with a physical item placed on a load sensitive surface which has embedded high precision scales. The link is maintained by reference to the weight of the physical item.
A common approach to capturing contextual information is through the use of location sensing. For example, computer vision has been used to identify the location of people, and to detect their activity. This location information may then be provided as contextual information to another information processing system.